Hydrodynamic balance feeder and method of feeding molten glass



F. L. o. WADSWORTH 2,131,242

C BALANCE FEEDER AND METHOD OF FEEDING MOLTEN GLASS Sept. 27, i938.l

HYDRODYN AMI Original Filed Feb. ll, 1935 2 Sheets-Sheet l Sep. 27, 1938. F, L. o. WADSWORTH 2,131,242

HYDRODYNAMIC BALNLE FEEDER AD METHOD OF FEEDING MOLTEN-GLASS Original Filed Feb. 11,1933 2 Sheets-Sheet 2 10a l J Q 7 97 105105-102l104 #www Patented Sept. 27, 1938 UNE'TED' STATES HYDRODYNAMIO BALANCE FEEDER AND METHOD" OF FE'DENG MOLTEN GLASS Frank L. (I Wadsworth, Pittsburgh, Pa., assignor to BallB'r'othersCompany, Muncie, Ind., a corporation of indiana Continuation of.k application Serial No. 656,306,

February 11; 1933.'

This application July 19,

1935, Serial No. 32,774

24 Claims.

My inventionrelates to automatic `glassfeeders or the hydrodynamic balancec'ontinuous-'lowk type which is describedinmy copendin'g applicae tion SerialNo; 653,081, led January 23, 19331' and is a continuation of an earlier`app'lication Serial No. 656,306, led February l1",'.l933;'and' one of the special'objects of this invention is to provide for the establishment'and c'onnement ofY ra definite quantity or mass ofelasticfluid'in the llfbalanee chamber of the apparatus at two predetermined intervals 'in each complete cycle of its operation. More specically stated my present improvements comprise the use of an inverted b'ell or cup, whose loweredge'is immersed in a body lSGo moltenY glass, and which' is adapted to be periodically reciproca-ted, and alternately moved toward and away from a submerged delivery orifice in the oor of the glass holding'receptacle; and of automatically actuated'means for mo- 2'0" mentarily equalizing thek pressure lof 'the air, which is conned in the upper part ofthe inverted bell or cup chamber (above the glass), withthat of anV outside body of fluid, at two predetermined positions of the reciprocating' implement; and thereby obtaining a double or dual controlfof'` the hydrodynamic balance forces which act to vary and regulate the flow of glass from the delivery orice. This' provision for periodically establishing a connection between the air chamber of the bell and an outside source of fluid pressure, at two dilerent points in they up and down movement ofthe said bell-and thereby establishing at each of those pointsof connection, a fixed relationship between the'volume and 35 the mass ofthe conned body of gas in` the bellV chamber-diierentiates the form' o'feeder hereinv described and claimed from that disclosed) 1n said earlier application Ser. No. 653,081, inwhich this equalization connection is effected at on'ly 4=0one point in the reciprocatory movement.

Another particular object and purpose ofthis invention is the provisionrof an improved formof superspeed cutting mechanism, in which the 4 Vtwo shear blades revolve continuously. in opposite directions and are periodically projected organization, that is depicted in the accompanying drawings, in which: Y Y

Figure 1 is a partial front elevation, and-a'- partial transverse section through the central vertical plane of the delivery orifice (i. egthe plane I-I of Figs. 3 and 4) of the feeder; Fig; 2' is an enlarged section (on the same plane)` of a portion of this construction; Fig. 3 is a hori zontal section on the plane III-III of'Fig. 1; Fig. 4 is another horizontal section, on lthe plane IV-IV passing through the lower part ofmy` im- -proved shear mechanism (see Fig. 5) Figi Bisa-l vertical section (partly in elevation) on the plane V-V of Fig. 4; and Figs. 6, 7, and' 8 arev secV tional views showing certain parts of thejshear mechanism in other positions.

In the form of apparatus shown in these drawings, the parent body of molten glass is contained in a suitable dog house, or forehearth cham--v ber, i, which extends out from the front or ning endy of a larger tank (not hereshow'n), and which is provided, near its forward extremity,v with a removable bottom block 2, that is raised slightly above the floor of the chamber I, andis adapted to itself support the usual form of ow ring or bushing F,.from which the glass is delivered to the forming mechanism.

The vertically reciprocable bell B, which, con-v tains the segregation and hydrodynamic balance chamber of the feeder, is mounted directly above, and in line with' the axis of, the flow orice' F, and is preferably provided with a beveled vend 3j, whichv is ladapted' to enter the correspondingly coned opening in the upper portion of the raisedA floor block 2, and cooperate therewith in controlling the flow of glass from the forehearth' l into the frusto-conical chamber D inthe bell B. The upper end of this bell is preferably ree duced in diameter, and passes upwardthrough ari-annular guard ring 4, inthe roof'ofthe cham-` ber l; and the annular space 5, Which'islleft between the lower end of this ring and the reduced Fahrite, and a central tubular bolt 8, of similar high resistivity alloy, which are clamped in position, on the clay body, by a nut 9 and a sleeve washer or head IIJ. The outer edge of the head I is coned, and is engaged by a set of three or more circumferentially disposed set screws Il, which, when tightened, clamp the bell assembly against the lower end of an elongated piston member I2, that forms a part of the actuating mechanism for the bell.

The piston element I2 is mounted in the lower part of the double open ended cylinder I3 and is connected, by the hollow piston rod I4, with a second piston I5, which is positioned above the central cross head I 6 of the cylinder I3. The upper and lower piston chambers are respectively connected, by the pipes II-I8, with a timer valve cylinder 2U, which is suppliedwith compressed air from a conduit 2l, and which is also provided with exhaust ports of the usual form; theV general construction of these timer valve mechanisms being so well known that it is unnecessary to` describe it in detail.

The cylinder member I3--I6 is provided with laterally extending box girder arms, 22-22, which are bored, at their outer ends, to slide freely up and down on the vertical screw members, 24-24, andwhich may be locked, in any desired position on these screws by the threaded nuts 2li- 26, 21-21. The screws 24-24 are rotatably mounted in the upper and lower cross struts 28-29, of the structural steel framework, which supports the metalfboot of the forehearth and the other parts of the feeder mechanism; and they are cross connected, at the top, by the transverse shaft 30, and the co-engaged bevel gears and pinions 3I-3I, 32-32. The lower pair of lock nuts, 26-26, are prevented from turning by dowel pin connections 33; and when the upper lock nuts, 2'I-2I, are loosened, the entire cylinder frame may be raised and lowered by revolving the pinion shaft 30.

The cylinder member I3 is also provided with an upper head 35, which is carried by a pair of U-shaped arms 36-36, whose outer ends are also bored to slide freely up and down on the screw rods 24--24; and which is held in the desired position with respect to its supports, by a pair of threaded gears 31-31, that are embraced by the forked extremities of the arms 36-36. The gears 31-31 are cross connected, for concurrent rotation, by the transverse shaft 38 and the helical gears 40-40. When the screws 24-24 are revolved (by the action of the shaft and pinion connections 30-3I-32, etc.), the head 35 will be moved up and down with the cylinder frame, I3-I6-22, etc.; but this head may also be adjusted verticallywith respect to the cylinder-by an independent rotation of the shaft and gear elements 38-40-40.

The cylinder head 35 carries a valve box 4I, which'has an internalconstruction that is best shown in the enlarged cross sectional View of Fig. 2, and which is connected with the hollow piston rod I4 by a small pipe connection 42 that is slidably engaged with the bore of the said rod I4. This box contains two poppet valve elements 43-44, that serve respectively to open or close communication between the pipe connection 42, and the two pipe connections 45-46, which lead to two independent sources of preadjusted subrently to the external air by means of the two two-way cocks 41-48,

The valves 43-44 are actuated, at predetermined times in the reciprocatory movement of the connected bell and piston members, B-I 2-I4-I 5, by the tappet levers 50-5I which are engaged by the pawl elements 52--53 that are mounted on and move with the upper piston head I; the construction and arrangement of these cooperating parts being such that on the downward movement of the piston the pawl 52 rides back and over the adjacentV end of the tappet lever 50, without moving the latter, and on the reverse upward movement it engages and moves this lever-and opens the valve 43-by an amount that can be varied by the adjustment of the screw 55. The pawl frame 54 is also adjustably mounted on its support 56, and by moving this up or down, the time at which the valve 43, is openedon the up stroke of the bell B-can be correspondingly altered. The action of the pawl 53, on the lever 5I, and the valve 44, is similar to that of the pawl 52 on the lever 50 but in this case no adjustments are provided for altering either the extent or the time'of opening the last-mentioned valve (44) on the down stroke of the bell B.

The moving elements of the timer valve member 20 are actuated in the usual way, by a timer cam 58 which is driven, at a controllable speed, from a suitable variable speed motor M; and this motor may also be used, when desired, to operate the overhead pinion shaft 30, through the manually operable clutch '60, and the sheave and rope connections 6I-62-63.

The operation of that portion of my improved feeder organization which has been described above, is as follows: v

When compressed air is admitted to the upper end of the cylinder I3-through the pipe connection II-the double ended piston members I2-I4-I5, and the bell B carried thereby, are moved upwardly; and in the initial part of this movement, the valve 43 is momentarily opened and then closed; thus establishing at a predetermined pointin the lifting of the bell, a definite pressure (viz, the pressure in the pipe connection 45) in the segregation chamber D. The establishment of this definite pressure, at this predetermined point, tends in turn to concurrently establish a definite relation between the level of the glass within the bell B and the xed level in the surrounding forehearth chamber; and the subsequent closing of the valve 43-as the upward movement continuestraps a definite predetermined quantity of the elastic uid above the surface of the segregated mass of molten material. The further upward movement of the bell tends to expand this coniined body of elastic fluid, and this in turn causes the glass to rise in the chamber D to maintain a condition of hydrodynamic balance--the rapidity and the extent of this rise being dependent in part on the viscosity of the molten glass and the speed of upward movement, and in part on the constantly increasing ratio between the area of the delivery orifice F and the area of the passageway (E) Ybetween the lower end of the bell B and the adjacent surface of the floor block 2.

When the connected bell and piston members have reached the upper end of their strokewhich is limited and determined by the engagement of the upper piston member I5 with the central hub of the head 35-the pressure in the segregation chamber (D) will be a minimum, and the corresponding level of the glass therein will be a maximum; and under these conditions the flow of material fromthe delivery orificewhich'v is--now in free and openV communication with;the parent body of molten glass in the forehearth` chamber-willbe controlled only by the action-of gravity. If now the movement of the bell-isrreversed (by the action of the timer valve in admitting compressed-air to the pipe connection I8,-.andin concurrently opening the connection II to the atmosphere)` the initial downward movement will momentarily open the valve l0 44, and thusrestablish, at another denite point in theY cycle of operations, a second predeterminedpressure in the segregation chamber (to wit, the. pressure in the pipe connection 48') ;A andthe subsequent closure of this valve, as the 15; downward movement continues, will againtrap aiixed mass ofelastic fluid abovethe glass in the bell; at. its upper level. The further downward movement of the reciprocating members will` tend to compress this conned fluid, and

20. correspondingly lower the level of the segregated massofglass on which it acts; and will Valso concurrently.v reduce the areaofthe passageway E and thereby increase the resistance to the back.

flow of glass into therforehearth chamber; and

ggfthe, joint eifect of these.Y two correlated actions will accelerate the discharge ofmolten material from the delivery orifice F, and swell-,or stuff the stream of outflowing glass. The viscosity of the molten material will cause a lag in the down- -fward movement ofthe glass within the bell-as compared with the movement of the bell itselfand this will result in a progressive increasefin the pressure in the segregation chamber, which will normally` reach a maximum at the lowest point 355m the stroke, and will continueto exert an ex- "the pipe connection 45; and the discharge of glass from the delivery orifice F will be correspondingly reduced, thus producing a temporary natural necking of the outflowing stream. But I,I preferably so adjust the relationship of the 5 parts, B-Z and 58-52, and so control the predetermined pressure n the pipe line 45, that the outiiowof glass is never completely arrested during the upward movement of the bell B; .but always continues at a substantial rate under the influence of gravity alone; the object of this continued, or non-arrested, flow being to increase the average rate of discharge per unit of time, and thus increase the delivery capacity of g the feeder without any abnormal or excessive swelling of the stream during the intervals of accelerated flow.

The lower limit oftravel. of the bell-which determines the area ofthe supply passage E at .0. the lowest'point in the stroke-can be easily ad- `5" justed, while the feeder is in operation, by a manual manipulation of the rope belt SZ-which will raise or lower the entire cylinder-pistonassembly-and the upper limit of" that travel may be independently adjusted by the manual rotation of the cross shaft 38" (which raises or lowers the cap 35) and the time, and the duration, of the'opening of the valve 43imay be-varied as desired in the manner alreadyexplained. The two predetermined pressures in the segregation chamber-at the two predetermined points in the* mechanical engagement with the wall,I6;

bell movement-maylikewise be regulatedlby the established' pressures inthe pipe line connections 45 and' 4;I5-' (and .to some degree also bythe two throttle'yalve controls, ISS- 65, therein) 1 or one oriboth of-these pressures may beA equalized with that ofthe outside air bythe proper setting ofthe two-way cocks 4'I and 48.`

The speed of the up and down movements of the reciprocating bellv may alsol be varied'and cont'rolledlby-Y the pressure in the compressed air line 2I,. andby the independent.vv adjustment oi?` the two swiveling throttle valvesl 66, 66 in the pipe connections II and I 8; andthe number of completeV reoiprocations per minute may be regulated` by the hand rheostat R on the motonM..

In Fig 1, I4 have also. shown a convenient means for cooling the lowerfend of the piston member I2, and the adjacent metal members, Ill-Larrd.;r I I,lby. the use. of the exhaust from' the lower.V p-istonlchamber.v In order to accomplish thisrlamake the lower,` piston member hollow, and. provide'` its upper, wall with an exhaust port 68, thatisA covered by a'V disc valve 69, thestem of which extends; upwardly through the central cross wall; I6 ofthe cylinder I3, and terminates in asmallfheadl.. `When the piston members I2..-I4-I5, are moving upwardly the disc 6I)` is.heldagainst its seat by thefrictional resist,`

ance to the movement of the valve stem through' its bearing in the crosswall I8; and when compressed air is admitted. to the lower piston chamber (through the pine connection I8) the disc is :held closed by this pressure, until the concurrentdownward movement of the pistonvalve--elements I2-59 brings the head I0 into The final downward movement of the pistonassemblywhichis limited by the engagement of the upper piston I5 with the cross wall I6-. thenopens the exhaust port' 68, and permits the compressed air in the lower piston chamber to rush out, through the hollow piston I2 and the ring` of ports II-'Hin the lower head thereof, and thus materially assist in protecting these parts against the action of any hot gases which may escape past the guard ring 4.

The preferred mode of operatio-n which has been described materially.r reduces the amount of natural necking or contraction of steam diameter; duringthe initial upward movement of the bell B, and in order to sever this stream without arresting its continuous ow, and without subjecting it to any appreciable cooling effect during such cutting action, I have provided,

as; another feature of my improved feeder construction, a novel type of high speed, or superspeed. shear mechanism which isadapted'to effect the severance in a very small fraction of the time usually required for such operations. One embodiment of this feature ofv my improvements is illustrated in Figs. 4to 8 of the accompanying drawings. In the construction here shown the two shear blades 'I5-'I6 (which may be either ofthe straightblade, or ofthe usual notched blade, catsf eye form) are removably'attachedr to twoV arms 'II and I8 that are respectively keyed to acentral vertical shaft 'I9 and an outer tubular sleeve 80, which are mounted to revolve concentrically in the bearing members 8| and 82 of a U-shaped frame 8,3. The connected members, 'l5-1I`I9, and 'I6-'I8-8 are continuouslyk rotated in opposite directions, at the same angularspeed, by two bevel pinions'85 'and' 86- (that aresecured respectively' tothe shaft 'I9 and the sleeve member 80)and an interposed bevel gear 817that is driven by the motor 88. A

-The member 83-which forms a common unity support for all of the above-described elements of the shear mechanismis adapted to rock, or

swing, on a vertical trunnion member 90, that is carried by the o-pen stem portion of a T-shaped frame 9|; and is provided with a forked arm 92 which is coupled, by the link 93, to the piston member 94 of a cylinder 95 that is supported on the head portion of this frame. The oppositely extending side of the T head carries a valve box 96, in which is mounted a reciprocable double piston valve, I-|0|, that serves to control the admissio-n and exhaust of air to and from the cylinder 95, and the resultant angular movement of the shear supporting frame 83. This control is effected as follows:

The front chamber of the valve box 96 is connected to the compressed air line 2| through a pipe 91, and a timer `valve assembly 98 that is actuated by a cam on the Same shaft that carries the timer valve cam 58 (see Figs. 1 and 3). A port 99.1eads from this part of the box 95 to the rear chamber in which the piston valve elements |00|0| are located;` anda second port and pipe connection |02 leads from the central part of this chamber to the rear end of the cylinder 95. The piston valve chamber is also provided with two exhaust ports |03 and |04 (see enlarged view of Fig. '1) which are positioned on opposite sides of the head |0l|and with a vent port |05 that is located in front of the head |00. The stem |09 of the piston valve member, |00--l0|, is reduced in diameter at the point where it enters the front chamber; and a disc valve element |08 is slidably mounted on this reduced portion, and is normally held in open position (against the adjacent face of the front chamber of the valve box) by the spring |09.

The lower part of the swinging frame support 03 is bored to receive a piston member ||0 that is provided at its front end with an arm or lug which forms a pivot support for a forked lever H2. The two arms of this lever are thickened or brought together, at their outer ends to form a narrow slot through which the piston valve stem |06 passes; and this stem carries an adjustable collar |14 that is adapted to be engaged by the thickened ends of the lever arms. The upper arm of the lever ||2 carries a cam roller 5, which is adapted to engage with a cam disc H6 onthe bevel pinion 85, when the piston |0 is moved forward to the position shown in Fig. 4.

The rear end of the piston (H0) cylinder is connected to the port 99 by the passageways IIS-I |9 and |20, which are formed in the hub of the swinging frame 83 and the stationary trunnion supports 90 and 9|. The piston ||0 is normally held in its retracted position-with the cam roller ||5 out of engagement with the cam disc IIE-by a spring |2|; and an .adjustable stop member |22 is provided to limit its forward movement. A second spring |25 which is attached t0 the end of the forked arm 92, serves to normally hold the shear supporting frame 83 in the full line position shown in Figs. 4 and 5; and in this position the path of movement of the shear blades does not intersect the line of iiow of the glass stream.

When it is desired to effect a severing operation, compressed air is admitted to the line 91 by the action of the timer valve 98; but is prevented from reaching the cylinder 95 by the piston valve head Inl, until theV latter Vhas vbeen moved fromthe position shown in Fig. 4 to that shown in Fig. `6.-

This movementwhich must be so timed that the continuously revolving shear blades meet and pass each other on the axis of the owing stream--isV eiTected by the piston-lever-cam elements |I0 ||2| |5-I I6. The admission of ycompressed air to the line 91, and the front chamber of the valve box 96--and thence to the ports and passageways 99-|20, etc-moves the piston ||0 forward and brings the cam roller ||5 into contact with the cam disc H6. The parts are so arranged and adjusted that the lobe of this camwhich is revolving clockwise as Viewed in Fig. 4--engages the roller l I5 at the time when the two shear blades have moved from the position shown in full lines in Fig. 5 (where the axis of one blade (15)-19, and the axis of the other (i. e., 16) is in the plane V-V) to the crossing position indicated b-y the dotted line 19-S; and when this engagement occurs, the lever ||2 is rocked to' the'right and moves the piston Valve elements |00|0| to the full line position of Fig. 6. This movement closes the exhaust port |03, and permits the compressed air to pass from the port 99 to the port |02 and to the rear of th-e piston 94. This immediately swings the shear frame assembly forwardly until it meets the adjustable stop |21 on the frame 9|, and the next revolution of the shear arms will cause the shear bla-des to meet and cross on the axis F (in the plane I-D of the owing stream, and almost instantaneously sever the latter.V As Vindicative of the very short interval required in this cutting operation, let us assumeas here shown-that the eiective radius of action is approximately '7.5 inches and that the speed of revolution is 1200 R. P. M. R. P. S.) The linear speed of each blade is then about 950 inches per second; and the time required to sever a two inch diameter stream is only a little more than 0.001 second.

After each severance it is, of course, necessary to immediately swing th-e shear frame back from its operative position; and this may be effected in the following manner: The cam disc ||6 is provided, on its lower side, with a pin or roller |30, and the Valve stem |06 with an adjustable cam block |3I; and these cooperating elements (|30-I3I) are so positioned that as the shear blades meet and cross, on the axis F, the pin engages the block |3| and moves the valve elements |00|0| to the left and intothe position shown in Fig. 7, this movement being sufcient to also close the disc valve |08 against the pressure of the springl |09. This movement shuts off the flow of compressed air to the port 99 and opens both of the exhaust ports |03 and |04, thus permitting the piston members 94 and |I0 to be immediately retracted, by the action of the springs |25 and |2l. The valve elements |00|0|I08 will, however, be held in their last-described posi'- tion, by the pressure of the compressed air on the l face of the discl valve |00, until the timer valve 98 acts to open the line 91 to the atmosphere; and when this occurs, the spring |09 will return the valve parts totheir original intermediate position (shown in Fig. 4) in readiness for the next operation.

It will be observed that the advance and the retraction of the shear blade assemblyto carry the line of movement of the blades into and away from the path of the owing stream--is not dependent upon any exact setting or adjustment of the timervalve mechanism, but is controlled and determined (after the timer valve is actuated to Vadmit compressed air to the-line 91) by the rotation of the shear arms themselves; and that any slight irregularities or momentary changes either in the action of the timer -valve cam, or in the Speed of the motor 88,cannot sensibly affect the interval between successive severing operations, or the establishment of a proper registration between the rotary and the transverse movements of the cutting elements.

Since the blades of my improved superspeed shear `mechanism are revolving continuously, and must of course cross veach other twice in each revolution, it is desirable to avoid bringing them into wiping contact except at such times as they are engaged in severing the glass stream. I Vaccomplish this object by interposing a light .spring I35 between'the adjacent faces of the arms 11 and 18 (see enlarged-view of Fig.8), and by providing abeveled end arm |36, which is supported by the fra'me 9|, and which extends out to vsuch a `position thatwhen Vthe frame 83 is swung forward to cutting position the end of this arm engages the coned or'rounded extremity of the shaft 19 and presses the upper shear blade arm 'I1 down against the lower arm 1.8; the shear blades themselves being so `shaped and so adjusted (as shown inFig. 5) 'that the cutting edges -will then ride up on each other, at the instant of crossing, and eiect a cleansharp unmarked severance of the molten material.

It is also desirable to provide for a vertical adjustment of the cutting plane with respect to the lower end of the delivery orifice F; and this result is achieved in the construction herein shown, by bolting the stem of the T-shaped frame 9! -against the face of abracket IME, which vis rigidly .ents.No. 1,311,474 (see-lines60-89, p. 1) andNo.

1,334,745 (see.lines-68-.105, page2) and therparticular .advantagesof `providing such-an adjustment in connection v:with .my hereinbefore described form-of .apparatus `willbe readily appreciated by-those skilled in .this art.

.It will be understood .that vthe .mode or. method of operation which characterizes Amy improved type of hydrodynamic balance feeder does not depend upon any adhesion of the glass to the surface of a reciprocating implement (as in the case of the sticky plunger feeder); and that the reciprocatingibell B (or its equivalent) may be made of a material'to which the molten glass will not adhere, withoutaffecting`its desired action. It will-also'be understood that'the operation "of this improvedtype of feeder does not involve any continued-How of air (or other uid) to and from apneumatic-pressure chamber (as in thecase of the Hitchcock-McCauley type offair feeder); nordoes it require theuse-.of auxiliary pumps, .or othermeans, -for maintaining such flow. .The bell itself, andthe .molten mass of glass segregated therein, togetherform the cylinder and piston elements of a .pump.which acts to supplement-the eiect-of-gravityin alternately expelling -the'glass from ythe .segregation lor balchamber.

lance chamber, and then rellingit from lthe My improved parent -body of fmolten material. `mode of procedure is further characterized -by the maintenance of a constant-or unvaried-area of opening through the discharge outleti. e.,

" this outlet-is never throttled or obstructed by `the'lower end of :a reciprocating implement, or

"obturator-and by a periodic increase andpdecrease in the area of the supply passage leading from the main bodyof glass to the segregation This progressive .change in the .ratio between ,the areas of these `two passages (the Ydelivery and the supply openings) cooperates with `the progressive changes of pressure within the bell chamber-which are themselves dependent only on the bellmovement-in periodicallyiaccelerating the extrusion of the glassfrom the .delivery `orifice .duringithe downward movement,

.and -in continuingr -this accelerated discharge vafter -thismovement has been arrested; 4.and in yalso -hastening the -low of glass fromv the ,sur-

namic balance y-ieedersdiiifer materially fromthat of 'thereciprocating plunger feeder and Lalso from that ofthe pneumatic impulseY (pressure The mechanical structure which lishereinfili .lustrated and described is only one ofmany which 1 of `construction which will embody the .whole or lpart Vof the improvements which are dened in thefollowing claims.

What I claimzis: l. An. improved-method vof .feedingmolten ,glass from a body thereof through anorice .submerged thereby which consists inconning a limitedpor- ,tion of the surface ofthe glass above. said orice, Vsuccessively subjectingthe confined surfaceto two felasticuids of predetermined and diiferentpres- 'Sures at predetermined times,A and progressively :varying v-each said 'fluid pressure duringthe in- A..

.terval between such successive applications.

2. ,2An improvement in the art of feedingmolten .glass-froma, parent body and through an orifice submerged thereby'which consists-in. confining a Vportion ofthe surface'of the glass-abovesaid .ori- Tice, subjecting such `confined surface to two successively applieduid pressures of ,predetermined but diierent magnitudes, progressively varying each of the pressures soapplied during the. inter- -vals betweentheir successive application to segregate glass abovesaid orice and to discharge such segregated glassffrom said orifice and varying the kresistance to the return. of the said segregated .glass to the parent source of supply during the discharge thereof -through said orifice. l

3. An improvementin the art of feeding glass from a parent body of the molten material Awhich comprises: confining a portion of the surface of said material within the interior of a reciprocating bell, .alternately subjecting the surface of glass Within-said bell to predetermined fluid pressures of different 'magnitudes during the movement of the bell in opposite directions, progressively varying the pressures of the fluid-withinsaid bell during the continued movement thereof, and utilizing the variations of pressure thus produced to periodically alter-theYrate-ofjlow of the glass from the bell to and through ardelivery .orifice adjacent thereto. Y

4. An improved .feeder for .viscous material whichY comprises the combination of a'receptacle for said material having a`delivery o'rice leading therefrom, a segregation chamber positioned above said orifice, means for reciprocating Vsaid chamber to successively admit limited quantities of the said material to the Vsaid chamber, and

means actuated by said chamber at substantially each end of its stroke for trapping predetermined fiuidpressures therein, the continued reciprocation gf said chamber being utilized to progressively vary the pressure of the said fluid during the periods between the successive admissions thereof, and thereby jointly controlling the admission of material torsaid chamber and its discharge therefrom.Y i

.5. An improved feeder of the class described, which comprises the combination of a container for molten material having an open well in the bottom thereof with the wall extending above the floor of said container, a reciprocable ,bell positioned above and adapted to enter said well, a conduit leading from the interior of said bell to two sources of fluid pressure of different magnitude, means for periodically vreciprocating the said bell, and means actuated by the movement of said bell in each direction for momentarily and alternately opening said conduit to the said sources to thereby` admit and trap .a predetermined Yfluid pressure/in the bell chamber.

6. An improved feeder of the character de scribed, Vcomprising in combination a container having a discharge orifice in theboitomthereef,

a reciprocablebell positionedabove said orifice,

a conduit connecting the interior of said bell to different sources of fluid pressure O fdierent magnitude, means for periodically reciprocating said bell, means operable as saidbell is moving Vaway from said orifice for momentarily connectingsaid conduitwith one of said sources o f fluid pressure to establish a predetermined pressure therein, thecontinued movement of saidbell expanding said fluid and progressively decreasing thepressure thereof and causing a flow of glass l into said bell and means operable as said bell lprogressively increasing the pressure thereof whereby the flow of glass through said Qrice is accelerated.

"1. An improvement in the art of feeding molten glass from a submerged orifice, which vconsists in reciprocating a segregation chamber positioned over said orifice, establishing a predetermined fluid pressure in said segregation chamber while moving said chamber toward the orice, continuing such movement of thel chamber to progressively compress the fluid therein to thereby progressively increase the pressure thereof and augment the gravity fioW through said orifice, utilizing such built up pressure to maintain aflow of glass through the orice at the end o fthe down stroke and start of the up stroke of said chamber', establishing a second predetermined fluid pressure of lesser magnitude in said segregation chamber during the up stroke thereof and then continuing this upward movement to progressively expand the fluid in said chamber and decrease the pressure thereof to set up a ow of glass from the parent body to said chamber while continuing the gravity flow through said orifice.

8. The combination with a glass container having a submerged orifice,`of a double 4operi-ended cylinder on said container, a piston member having a portion slidably mounted in each end of said cylinder, a bell-shaped impeller attached to said piston and extending into said container abovesaid orifice, means Vfor movingsaid piston back and forth in said cylinder to reciprocate said impeller, means for connecting the interior of said impeller to two sources of fluid pressure,'and means carried by said piston for momentarily and successively actuating said last-mentioned means.

9. The combination with a glass container having an open Well in the bottom thereof with the wall extending above the floor of said container, of

a double open-ended cylinder on said c ontaineiila piston-like memberhaving a portion slidably mounted in each end of said cylinder, a bellshaped impeller extending into said container and adapted to enter said well, a conduit leading into the interior of said impeller to two sourcesof fluid i pressure of different magnitudes, means for moving said piston back and forth in said cylinder to raise and lowersaid impeller, and means adapted to be operated by said piston at each end of its stroke for momentarily opening said conduit to said sources to thereby admit and trap a predetermined quantity of elastic fluid in the impeller. 'o

l0. An 4improvement in the art of feeding molten glass through an orifice submerged by a body of such material which consists inv segregating a quota of materialfromthe body'while `maintaining a gravity flow through the orifice,

periodically subjecting thesurface of such segregated quota to a predetermined fluid pressure and trapping a quantity of fluid under such pressure above the segregated quota, decreasing "the volume of the trapped uidto incre'aseothe pressure thereof and expel a portion ofthe segregated quotathrough Athe orifice, subjecting the surface of the remaining nportionof theY segregated 'quota to a fluid pressureoflessmagnitude than that of fluid pressure firstv applied, and trapping a quantity of fluid undersuch, pressure above the remaining portion of said segregated quota and thenI expanding the Asecond trapped fluid to Adecrease the pressure thereof andreestablish Ya flow from the supply b,o d y and segregate another quota therefrom. ,c 11. An improvementin the artl ofY .feeding molten4 glass through ran orifice submerged by .a

body of suchmaterial which consists in segregating a quota of material from the body while maintaining a gravity flow therefrom Athrough the orifice, establishing a predeterminedlfluid Vpressure above the segregated quota, varying the lcomprising in combination a container for molten material having a Adeliveryorif'lce.in the bottom thereof, a bell reciprocably mounted above'said orice andin vertical alignment therewith, a cylinder and piston associated With said bell, means formoving said piston back and forth in said cylinder to reciprocate said bell, and means Til Cal

actuated by-'the movement of said piston in 'each direction for momentarily and alternately connecting the interior of said bell 'to two sources of fluid pressures of different magnitudes.

13. An improved feeder for viscous material comprising in combination a container for molten material having a delivery orifice leading therefrom, an air bell positioned above said orifice, means for reciprocating said bell, means responsive tothe reciprocation of said bell for momentarily connecting the interior thereof to two sources of elastic fluid maintained under different pressures whereby limited quantities of such fluid are trapped in said bell at predetermined intervals, and means cooperating with said bell to vary the resistance of flow between the interior of said bell and the body of material within said container.

14. A glass feeder comprising a container for molten glass having a submerged discharge outlet therein, a bell extending into said container in axial alignment with said outlet, means for reciprocating said bell toward and away from said outlet to thereby vary the area of the passage between said bell and the bottom of said container, and means responsive to the reciprocation of said bell for momentarily and alternately connecting theinterior thereof to two sources of elastic fluid maintained under different pressures whereby limited quantities of such fluid are trapped in said bell at predetermined intervals.

15. A glass feeder comprising a container for molten glass having a submerged discharge outlet therein, a bell extending into said container in axial alignment with said outlet, means for reciprocating said bell to move the bell toward and away from said outlet and thereby vary the area of the passage between said bell and the bottom of said container, means responsive to the movement of said bell in a direction to restrict said passage for trapping a predetermined fluid pressure therein, and means responsive to the movement of said bell in a direction to open said passage for trapping a second but different predetermined fluid pressure therein.

16. An improvement in the art of feeding glass from a parent body through an orifice submerged thereby which consists in confining a portion of the surface of the body of glass over said orific'e within a reciprocating bell, establishing a predetermined fluid pressure within said bell at a predetermined point in the upstroke thereof, establishing a predetermined fluid pressure within said bell at a predeteermined point in theV downstroke thereof but of greater magnitude than that established on the upstroke thereof l and continuing the reciprocation of said bell to progressively vary the iiuid pressures within said bell during the intervals between their successive applications.

1'7. The method of feeding molten glass from the parent body through an orifice submerged thereby which consists in confining a portion of the surface of the glass above said orifice within a vertically reciprocating bell, equalizing the pressure within said bell with-a source of fluid pressure .at a definite point in the upstroke of said bell, continuing the upward movement of Vsaid bell to vary the pressure of the iiuid within said bell, equalizing the pressure within said bell with a second source of iiuid pressure of greater magnitude than said first mentioned source at a denite point in the downstroke of said bell, and continuing the downward movement of said bell vto varyfithe pressure within said'bell-,andaccelerate'theflowthrough the orifice. Y

18. An improvement inrthe -art of feeding molten lglass through an orifice submerged by a body of such material, which consists in confining a portion of the surface of the glass over'the orifice iiuid at a predeterminedpoint'in the upstroke thereof, drawing-glass into said bell from said' body by decreasing the pressure of the elastic fluid therein during the continued upward movement thereof, momentarily connecting the interior of said bell with a second source of elastic iiuid maintained under a higher pressure than said first mentioned source at the beginning of the downstroke thereof, expelling the glass from said bell by increasing the pressure of the fluid therein during the continued downward movement thereof and concurrently restricting thev flow from the supply body to the orifice and then removing the restriction from the supply body to the orifice while relieving the compression within said bell.

19. Glass feeding apparatus comprising .a container having a delivery orice in the bottom thereof, a bell reciprocably mounted abovev said orifice, means for reciprocating said bell, means for momentarily connecting the interior of said bell to two sources of elastic uid maintained under different pressures in timed relation tothe reciprocation of said-bell, means cooperating with the mouth of said bell for varying the resistance of flow between the interior-of said bell and the body of material within said container, and means for varying the relation between said last mentioned means and the mouth of said bell.

20. Glass feeding apparatus comprising a container for molten glass having a submerged discharge orifice therein, a bell projecting into said container in alignment with said orifice, a piston connected to said bell, a cylinder in which said piston reciprocates, means for delivering motive fluid to said cylinder, and means for raising and lowering said cylinder to vary the stroke of said bell.

21. Glass feeding apparatus comprising a containerhaving a submerged delivery orifice therein, a bell projecting into said container in alignment with said orifice, a piston connected to said bell, a cylinder in which said piston reciprocates, means for raising and lowering said cylinder to vary the stroke of said bell, valvular means for momentarily connecting the interior of said bell to two sources of elastic iiuid maintained under different pressures, and means for operating said Ycation of said bell.

22. Glass feeding apparatus comprising a container for molten glass having a submerged orifice therein, a bell mounted to reciprocate above said orifice, means for reciprocating said bell, a conduit for connecting the interior of said bell with two sources of elastic iiuid maintained under different pressures, valves vfor controlling communication between the interior of said bell and ther sources of elastic fluid, and means for operating said valves in timed relation to the reciprocation of said bell. f Y

23. A glass feeding apparatus comprising a forehearth having a submerged delivery orice therein, a bell mounted for reciprocation above said orifice, means for reciprocating said bell, a conduit connecting the interior of said bell with two sources of elasticy fluid maintained under CFI different pressures, valves for controlling communieation between said conduit andeach of said sources, means for operating one of said valves during the upstroke of said bell, and means for operating the other of Ysaid valves during the downstroke of said bell.

24. A glass feeding apparatus comprising a forehearth having an orice in the bottom thereof, a bell mounted for reeiprocation above said l0 orice, a piston attached to said bell, a cylinder 

